Here are some links to sites that describe different types of crude oil.
First, we have Platt's Oil Guide which gives a general description of crude types from around the globe. Note especially the API gravity for each type. The bigger the number, the lighter the crude and hence the ease with which it can be refined into a wide range of consumer products.
Second, here is a link to Hibernia and Terra Nova crude specifications. Go back and compare the stuff from these wells with other crude types.